July 2002: Labour issues another pledge card in the election campaign that resulted in Labour's re-election and National recording its worst-ever level of political support. It was not widely known at the time, but Labour says now it used parliamentary funding for its pledge card in 2002 and 1999.

Post-July 2002: Concern over National's extensive use of its Parliamentary funding for campaign material, such as bill boards and pamphlets, sparks MPs to rewrite the rules. After the furore erupts in 2006, National says the rewrite shows Labour knowingly broke the rules in 2005. Labour says the changes were not relevant and it complied with the rules as it understood them.

August 2005: In the run up to the election Labour launches another pledge card. It later emerges that it was warned by the then Chief Electoral Officer David Henry that it should be considered an election expense. This would have put Labour over the election cap.

September 2005: A number of complaints are made to the Electoral Commission about Labour and others over breaches of electoral law.

October 2005: Mr Henry refers numerous complaints to the police over breaches of election law concerning the nature of advertising and how it was funded.

December 2005: National admits it made a mistake over GST and has broken the broadcasting spending cap. It is also being investigated by the police for this.